diff --git a/libavcodec/x86/cavsdsp.c b/libavcodec/x86/cavsdsp.c
index 681d16afce..190f6eed66 100644
--- a/libavcodec/x86/cavsdsp.c
+++ b/libavcodec/x86/cavsdsp.c
@@ -139,7 +139,7 @@ static inline void cavs_idct8_1d(int16_t *block, uint64_t bias)
 static void cavs_idct8_add_mmx(uint8_t *dst, int16_t *block, int stride)
 {
     int i;
-    DECLARE_ALIGNED(8, int16_t, b2)[64];
+    DECLARE_ALIGNED(16, int16_t, b2)[64];
 
     for(i=0; i<2; i++){
         DECLARE_ALIGNED(8, uint64_t, tmp);